Managed Aquifer Recharge to Refill Groundwater Reservoirs

Watering coffee plants during the blooming stage is vital in the Central Highlands. Without proper irrigation flowers remain small and prone to wilthing. They wouldn’t develop into good cherries. Which would mean poorer yields and lower income. No wonder almost all ground water in Central Highlands is used up by farmers for coffee irrigation by the end of dry season, so that local residents face severe water shortages in March and April.

“For the first round of irrigation there is usually enough water, but for the second and third rounds we need to wait for up to ten days till some water appears again in our well. As for the water for household consumption we have no choice but deepen our well by a few meters every year. This is the only way to provide water for our everyday needs” – says Nam, the farmer from Krong Buk district in Dak Lak province.

At the same time the global demand for Robusta will grow by 30% in 2025, and Vietnam – the world biggest Robusta exporter – is expected to increase the production volumes. How is that possible if water scarcity is already heavily affecting the region?
After a series of baseline studies HRNS experts and their partners from Nestlé, SDC and University of Neuchâtel have found a solution. Instead of letting the rain water disappear in the streams and rivers there is a way to redirect it right into farmers’ wells through the system called Managed Aquifer Recharge (MAR). Similar systems have been successfully implemented in the USA, Netherlands, India, South Africa, and Australia.

The idea of MAR is simple. The water is streaming down the slope through a channel and into a barrel. The barrel contains a hand-made filter consisting of a few layers of gravel and sand to remove unwanted particles from water. From the filtering tank water gets into a pipe that brings it down into the well, replenishing the groundwater reservoir.

The benefits of MAR are numerous. First of all, the installation is fairly cheap and any farmer can afford it. Secondly, the system is very simple and gravity fed so farmers don’t have to spend any energy to make it work. And finally, MAR has no mechanical parts, and therefore is easy to maintain.
Nam from Krong Buk is one of six pioneers who decided to join the MAR project. The whole process of installation took just a few days:

“We dug a trench, installed the pipes and filled the barrel with multiple layers of stones and sand to make a filter”

In order to monitor MAR’s efficiency in various conditions HRNS arranged installations at six locations. All pilot stations will be monitored by the team of experts to evaluate the amount of water collected, quality of water and efficiency of filters.

If the pilot MAR stations bring sufficient amounts of clean water back to the underground reservoirs, more and more farmers will be encouraged to take up HRNS’s initiative, boosting up their coffee yields and leaving water shortages in the past.